Confidence Interval Exploration

sample mean

75

confidence (percent)

90

standard deviation

10

sample size

49

Use the sliders to change the various quantities that go into determining the confidence interval for the population mean and see how the upper (red) interval is affected. The lower (blue) interval was found using the default starting values and remains unchanged for comparison purposes. The intervals are approximate, and for small samples require some normality in the underlying population to be good approximations.